Need Help with a Circuit

Thread Starter

Tony Stauffer

Joined Apr 22, 2020
This is a 40 year old circuit for a Calor-Emag IS Limiter. I believe it's a type of AND gate based on the literature, but I can't confirm that. I haven't used my component-level electronics knowledge in nearly 20 years, and I'll be damned if I can figure this one out. The blue line is an input from a Scmitt trigger, the black line is an output to a Schmitt trigger, the red line is connected to the negative node of a full wave bridge rectifier as part of a current-sensing circuit, the green line is an input from a normally open relay contact, and pin 12 is connected to a 150VDC source. Any help would be greatly appreciated.

Mod: rotated the image.
Last edited by a moderator: